Blueprism to PAD Migration Output Details
This article describe Blueprism to Power Automate Desktop (PAD) specific conversions explanations. For generic conversion information, read Working with Migration Output in Power Automate Desktop (PAD)
Collections Conversion
Collections in Blueprism have two primary interfaces which differ quite a bit from a typical list or array. For example, a single row collection behave like a dictionary/custom object. The properties within the object in row 0 can be accessed as a key/value pair. In other to replicate this behaviour Blueprint converts collections into a Custom Object with the following signature:
{ "Counter": 0, "Items": [] }
Selectors
PAD supports the following attributes and technologies when converting selectors from Blueprism
Technology | Attributes | Notes |
Web | ElementType, InnerText, MatchIndex, PageAddress, Src, Name, Class, Id, XPath, InputType | A backup selector is created using XPath |
UIA | ControlType, Name, MatchIndex, AutomationId, ClassName, LocalizedControlType, Enabled, | |
AA | Role, Enabled, Name, Visible, Id, ClassName, MatchIndex | Direct support not yet available in PAD. |
Java | Conversion not supported. Different Java technology is used in PAD | |
SAP | Id | |
Region | Images are used where native PAD actions for images exist |
When possible Blueprint will create multiple selectors per UI element to increase the possibility of a match.
Blue Prism to PAD Error Handling
- BP to PAD Local Exceptions
Example from BP | Example Migration in PAD |
 | The purpose of the Recover stage in Blue Prism is to catch errors within the Block it's a part of. For Instance, in the BP screenshot all the errors are occur within the Block are considered "local" and are caught by Recover stage. This screenshot for PAD migration shows the use of On Block Error action, which is equivalent to Try and Catch Block.  If an error occurs within the On Block Error, we trigger similar error handling to what was set up in Blue Prism. The error details are recorded in the _LastError Variable. We Use Stop Flow action instead of Convert text to number: 1/0 when Throwing or Rethrowing an error.  If no error is found, or the error has been handled, then the flow will resume. The action which is causing the flow to resume back in Blue Prism is called "Resume". In PAD, this Resume resets the On Error variable to False and resumes the flow.  |
- BP to PAD Global Exceptions
Example from BP | Example Migration in PAD |
 | In Blue Prism, if a Recover stage is placed outside of a Block, it will function as global error handling. The purpose of Global Recovery is to catch any error that has occured outside of blocks. For Instance, any error found outside the block 1 could be considered under Global Recovery.  _LastError variable is used to store the error details. We Use Stop Flow action instead of Convert text to number: 1/0 when Throwing or Rethrowing an error.  If no error is found, or the error has been handled, then the flow will resume. The action which is causing the flow to resume back in Blue Prism is called "Resume". In PAD, this Resume resets the On Error variable to False and resumes the flow.  |
- BP to PAD Multi Entry and Multi Exists
Example from BP | Example Migration in PAD |
 | In Blue Prism, processes can be created with error blocks that have multiple entries and exit points. To make an equivalent in PAD, we need to flatten this down to a linear structure with the use of Set Variables, Ifs, and Go Tos. For Multiple Entries into an On Block Error, we create the variable Entry Destination and use it in If statements to determine the entry path. For Instance: In the below example, we are using the Entry Destination variable in If and elseif to determine what action/path will run next.  Similarly, if there are multiple exit points, we create the variable Exit Destination to decide the exit path. For Instance: In the below example, we are using If and elseif to check if the Exit Destination variable to determine what action/path will run next.  |
- BP to PAD Exception Type and Details
Example from BP | Example Migration in PAD |
Preserve Current Exception  | In Blue Prism, users can manually throw an exception with the Exception stage. Within it, there is the option to preserve the current exception type by selecting the Preserve Exception option, which will get whatever the the last exception message was and where it occurred on the page. In PAD, this is migrated as an If statement. The _LastError variable will retrieve the last exception details (saved in _Lasterror). In the screenshot, OnError is a variable set to False to retrieve the last exception message. However, if the user chooses to log the exception in Blue Prism with custom details and the Preserve Type unchecked, the custom Type and Details will also be migrated.  |